Clogged air filter element	Replace element according to engine manufacturers recommendations
								Obstructed air intake duct to turbo compressor	Remove obstruction or replace damaged parts as required
								Obstructed air outlet duct from compressor to intake manifold	Remove obstruction or replace damaged parts as required
								Obstructed intake manifold	Refer to engine manufacturers manual & remove obstruction
								Air leak in duct from air cleaner to compressor	Correct leak by replacing seals or tightening fasteners as required
								Air leak in duct from compressor to intake manifold	Correct leak by replacing seals or tightening fasteners as required
								Air leak at intake manifold to engine joint	Refer to engine manufacturers manual & replace gaskets or tighten fasteners as required
								Obstruction in exhaust manifold	Refer to engine manufacturers manual & remove obstruction
								Obstruction in muffler or exhaust stack	Remove obstruction or replace faulty components
								Gas leak in exhaust manifold to engine joint	Refer to engine manufacturers manual & replace gaskets or tighten fasteners as required
								Gas leak in turbine inlet to exhaust manifold joint	Replace gasket or tighten fasteners as required
								Gas leak in ducting after the turbine outlet	Refer to engine manufacturers manual & repair leak
								Obstructed turbocharger oil drain line	Remove obstruction or replace line as required
								Obstructed engine crankcase vent	Refer to engine manufacturers manual, clear obstruction
								Turbocharger center housing sludged or coked	Change engine oil & oil filter, overhaul or replace turbo as required
								Fuel injection pump or fuel injectors incorrectly adjusted	Refer to engine manufacturers manual - replace or adjust faulty component(s) as required
								Engine camshaft timing incorrect	Refer to engine manufacturers manual & replace worn parts
								Worn engine piston rings or liners (blowby)	Refer to engine manufacturers manual & repair engine as required
								Internal engine problem (valves, pistons)	Refer to engine manufacturers manual & repair engine as required
								Dirt caked on compressor wheel and/or diffuser vanes	Clean using a Non-Caustic cleaner & Soft Brush.  Find and correct source of unfiltered air & change engine oil & oil filter
								Damaged turbocharger	Analyze failed turbocharger, find & correct the cause of failure, overhaul or replace turbocharger as required

Normal Use

Acceptable operating & maintenance procedures

Contaminated oil (dirt in oil)

Engine oil and oil filter(s) not changed frequently enough, unfiltered air entering engine intake, malfunction in prelube valve or oil filter bypass valve

Severely contaminated (dirty oil)

Pounded by eccentric shaft motion

Foreign object damage, coked or loose housing, excessive bearing clearing due to lube problem

Center housing bearing bores, rough finish

Incorrect cleaning of ctr. hsg. during overhaul of turbo.  (Wrong chemicals, bores sand or bead blasted)

Metal or large particle oil contamination

Severe engine wear.  i.e., Bearing damage, camshaft or lifter wear, broken piston

Lack of lube, oil lag, insufficient lube

Low oil level, high speed shutdowns, lube system failure, turbo plugged w/ R.T.V.

Coking

Hot shutdowns, engine overfueled, restricted or leaking air intake

Fine particles in oil (contaminated oil)

See contaminated oil

Rough bearing journals on shaft

Bearing journals not protected from sand or bead blast cleaning during overhaul